According to a report from The New York Times, an unnamed Volkswagen executive said the automaker pays less than $100 per kWh for its batteries.
Tesla's "most ardent believers" will soon realize that the company "is not a viable business," said EdMcCabe of Highbridge Capital Managemen.
Tesla made three of the five best-selling electric vehicles in the US this year through June, according to the electric-vehicle website InsideEVs.
Both of the luxury automakers are flagging some of their electric vehicles because of potential safety issues.
Fiat Chrysler has proposed a major deal to make significant changes to the global auto industry in merger talks with fellow carmakers Nissan and Renault.
Electric vehicles from Audi, Mercedes-Benz, and Volkswagen have reached significant milestones in recent weeks.